Barriers to achieving gender equality in the STEM field are multifaceted, and their potential solutions are no less complex. While numbers of women in STEM have increased in recent years, women continue to both join the field at lower rates than men, and leave the field at higher rates. The results are discouraging, with just 14.4% of STEM occupations in the UK filled by women, according to the Women in the STEM Workforce's 2015 survey. What's even more troubling is the fact that many of these women leave the field before their mid-30s. This part of the problem - the struggle to keep women in the field once they join - requires targeted and disruptive innovation to overhaul.

Research from the Center for Talent Innovation shows that women working in STEM fields are 45% more likely than their male peers to leave the industry within a year. It's not the type of work that's pushing these women out though. In fact, 80% of the women surveyed reported loving their work. Instead, surveyed women explain it's the conditions at work - not the work itself - that's driving them out. Studies reveal that women leaving the STEM field often cite a similar grievance: an unwelcoming and exclusive work culture reinforced by gender stereotypes, in-group favouritism, and mysterious career paths.

With women tending to leave the field mid-career - just when it's most costly for their companies to replace them - investing in retaining women is more cost-effective in the long term. Keeping women in STEM isn't just the right thing to do; it's the smart thing to do. Research demonstrates that higher levels of gender diversity can lead to enhanced business outcomes, increased sales revenues, and greater relative profits. Studies have also shown increased levels of innovation, creativity and overall success on teams with equal numbers of men and women.

So how do we drive a more inclusive STEM culture? And in what innovative ways can we incubate and advance women in the field? Here are my thoughts:

1. Mentor Mid-Career Women

In-career mentorship by senior women is critical to women's success in the STEM field. Mentorship by someone that looks like you can alleviate career-path confusion and increase job satisfaction. And yet, significantly lower numbers of women than men report having office or field mentors at any point in their careers. According to a survey by LinkedIn, nearly one out of five women say they've never had a mentor at work, and an EMBO report found 45% of women in science, engineering and technology positions lack mentors.

Most STEM mentorship programmes focus on attracting young girls to the field through high school, college and early career programmes. Mentorship isn't just important as a budding STEM professional though. These types of relationships are critical for mid-career women to visualise their futures and seek advice on overcoming barriers as women in male-dominated fields. It's during the mid-career stage, when personal and professional responsibilities tend to rev up, that women tend to leave the field. In fact, over 50% of women in technical roles quit at the mid-career point.

To reap the lasting benefits of female employees, corporations need to invest in encouraging female mentorship programmes and spotlighting female role models in senior positions. Highlighting women at the top, and encouraging mid-career women to seek these senior women as mentors, will help demystify the unclear career path for women in STEM and encourage women to stay in the field.

2. Reintegrate Women after Maternity Leave

Women leaving the STEM world often cite motherhood and issues surrounding maternity leave as major contributors in their decisions to leave. A recent Tools for Change study showed that nearly two-thirds of female scientists with children felt they experienced a "maternal wall", during which their competencies and commitment were challenged, and their opportunities for advancement began to diminish. Coupled with anticipated difficulties returning to the fast-paced and quick-evolving sector after time off, STEM women often choose this juncture to leave the field.

Making new mothers feel welcome in a company isn't just about having a maternity policy or paid leave though, it's about showing women that returning to the field as a new mother, and balancing their new family responsibilities with their old work responsibilities is both possible and encouraged. Pre-leave programmes like offering mothers-to-be information about maternity leave options, allowing for flexible hours for doctors' appointments, and connecting them with networks of other mothers in the field can help reassure women in STEM that their careers will be waiting for them when they return. Similarly, post-maternity leave programs like flexible office hours, options to telecommute, and family friendly facilities such as on-site day care centers and breast-feeding rooms can significantly increase companies' retention of mid-career female STEM workers.

3. Involve Men

In a Case Western Reserve University study, researchers found that over half of technical women surveyed cited a "hostile macho culture" as their top reason for leaving the field. The culture, they explained, marginalises women as the "out-group" thus excluding them from key-networks and potential promotional opportunities. To tear down these barriers to women's success in the STEM field, we must engage men as agents of change.

We need active efforts to reduce bias and sexism in STEM workplaces, and we need targeted efforts to find and promote capable women to leadership positions. To reduce bias, organisations can promote innate bias testing and mandate office-wide educational programmes to teach staff about the harmful effects of stereotyping and sexism. To promote female-leaders, male executives need to actively engage on projects with mid-career women and seek out female talent within their organisations, breaking out of their "in-group" and sourcing talent from the wider pool.

Involving men in empowering and advancing women in STEM is critical to jump-starting and sustaining cultural change in the field. As is encouraging and reintegrating women returning from maternity leave, and nurturing mid-career talent through mentorships and women's networks. If corporations take innovative and targeted efforts to retain their women - such as the initiatives discussed here - we could create a more inclusive STEM culture where women, and their companies, will thrive.

Fumbi Chima is CIO at Burberry, a Board Member of the World Affairs Council in Washington DC, a member of the United Nations Digital Taskforce, and an Advisory Board Member of global affairs media network Diplomatic Courier.